Avaliação da produção de hidrogênio e metano a partir da codigestão anaeróbia de resíduos

Abstract

The sequential production of hydrogen and methane through anaerobic codigestion in two phases (acidogenesis and methanogenesis) of organic waste (OW), sewage sludge (SS) and raw glycerol (GL), was investigated in batch assays under temperature controlled conditions. The effect of glycerol addition (1 and 3% v/v) as cosubstrate was assessed in binary (SS+GL and OW+GL) and ternary (OW+SS+GL) mixtures. No hydrogen was generated from the co-digestion of the mixture of sewage sludge and glycerol. However, the presence of GL (1 and 3%) increased the hydrogen production in all tested conditions (OW+GL and OW+SS+GL) and reduced the acclimation time (lag phase) in around 4 hours in comparison with the tests carried out without this co-substrate (control experiment). Maximum hydrogen production was found to be 179 mL H2/gVS and 260 mL H2/gVS, obtained for the OW+GL and OW+SS+GL mixtures employing 3% GL, respectively. On the other hand, the highest methane production was 301 mL CH4/gVS e 377,4 mL CH4/gVS, values obtained with the binary and ternary samples with 1% GL. The co-digestion of organic waste, sewage sludge and raw glycerol has shown to be promising and can be potentially used to maximize energy production, while contributing for the management and treatment of these residues.